/Engine/Source/Editor/UnrealEd/Classes/MaterialEditor/MaterialEditorPreviewParameters.h
Creates/adds value to group retrieved from parent material .
void AssignParameterToGroup ( [UDEditorParameterValue](API\Editor\UnrealEd\MaterialEditor\UDEditorParameterValue) * ParameterValue, const [FName](API\Runtime\Core\UObject\FName) & GroupName )